Mesoscale Discussion 1861
   NWS Storm Prediction Center Norman OK
   0946 PM CDT Thu Oct 14 2021

   Areas affected...Much of central Oklahoma

   Concerning...Severe potential...Watch unlikely 

   Valid 150246Z - 150515Z

   Probability of Watch Issuance...20 percent

   SUMMARY...An area of increasing thunderstorm activity may evolve
   into a small organizing cluster near the Interstate 40 and 44
   corridors, across and east-northeast of the Oklahoma City
   metropolitan area, through Midnight-2 AM CDT.

   DISCUSSION...Ahead of a southward advancing cold front, large-scale
   ascent driven by lower/mid-tropospheric warm advection appears to be
   in the process of strengthening across southwestern into central
   Oklahoma.  Latest model output suggests that, as this continues to
   develop east-northeastward through late evening, it may become
   augmented by forcing for ascent associated with a focused area of
   increasingly divergent upper flow, between a pair of coupled,
   cyclonic upper jets across the central and southern Great Plains.

   The primary mid-level short wave impulse, and colder mid-level air,
   may pass to the northwest of the region, and an initially warm,
   subsident layer, based near or below 500 mb, may hinder
   destabilization.  However, deepening low-level moisture return,
   above a boundary-layer stabilizing with the loss of daytime heating,
   is expected to become sufficient to support the initiation of an
   upscale growing cluster of thunderstorms near the Oklahoma City
   metropolitan area by 04-06Z.

   Due to the weak mid-level lapse rates, supportive of only weak to
   perhaps modest CAPE (generally on the order of 500-750 J/kg), and
   stable near-surface layer, potential for severe hail and wind seems
   low, but remains uncertain.  Much may depend on strengthening of
   low-level flow and the extent of low-level hodograph enlargement in
   the vicinity of the developing cluster.  Most model output has
   suggested that this will remain relatively modest, but with perhaps
   a mesoscale area of strengthening that could support substantive
   updraft rotation and storm organization, particularly east-northeast
   of the Oklahoma City overnight.

   ..Kerr/Guyer.. 10/15/2021

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...TSA...OUN...

   LAT...LON   35379873 35949733 36179631 35519561 34979712 34999859
               35379873